The compound 1,3-dihalo-4,6-dinitrobenzene (“DHDNB”), which is represented by the structure of the following Formula (I),

wherein each X is independently Br or Cl, is conventionally used as a starting material or intermediate in the preparation of a variety of products that include dyes, pharmaceuticals, pesticides, agrochemicals, and monomers for incorporation into polymers such as those described in WO 94/25506.
Known processes for the preparation, for example, of 1,3-dichloro-4,6-dinitrobenzene (“DCDNB”) by the nitration of 1,3-dichlorobenzene, which is represented by the structure of the following Formula (II)
require a costly work-up procedure (“quench”) wherein the product and sulfuric acid reaction mixture is added to a large quantity of ice and/or diluted with 5-10 times the volume of water. The large volumes, the difficulty of managing the exotherm associated with this quench procedure, and the difficulty of recycling the sulfuric acid result in considerable fixed and variable cost. It would thus be desirable to be able to eliminate the need for such a quench procedure.
For this reason, and because of a particular need for a process to make DCDNB with improved selectivity and high purity, a need remains for improved processes generally to make the various compounds of Formula (I).